The present invention relates generally to a foldable, portable load-carrying structure, and more particularly to such a structure which may, for example, be used as a portable bridge over leads in Arctic ice regions.
In the Arctic, the ice surface is frequently used to drive, walk and work on. A major problem is that changing conditions such as wind and thermal expansion often cause the ice to break apart, causing leads that are like rivers of open water. these leads may be up to twenty feet wide, and they create a problem when they open up along a route used to transport supplies. It would be desirable to have a system for crossing these leads which would: not take more than eight hours to deploy or retrieve; accomodate the most likely lead of from 5 to 8 foot in width and the largest likely lead of from sixteen to twenty foot in width; be transportable in an aircraft; be buoyant; accomodate fifty thousand pound loads; accomodate loads up to twelve foot wide; accomodate maximum wheel widths of eleven and one half foot; and be able to survive rough treatment and extreme temperatures down to minus sixty degrees Fahrenheit.